This invention relates to a video signal transmission apparatus adapted for allowing digital video signals to undergo transmission through a data recorder, etc. to thereby have ability of transmitting/receiving video material (data) of the synchronous transfer system through a transmission path by ATM (Asynchronous Transfer Mode) such as B-ISDN (Broad band aspect of Integrated Services Digital Network), etc.
Hitherto, in transmission of news material (data) of the broadcasting station, etc., because emergency is required, from a viewpoint such that adherence to high picture quality (mainly in the case of analog transmission; picture compression is used by the requirements based on the transmission band in the case of the digital transmission) is not particularly made, video materials photographed or image-picked up at the photographing field (site) are transmitted directly or after undergone editing, through channels of SNG (Satellite News Gathering). By employing such a transmission system, times required for delivery (transfer) of video materials of this kind are shortened, so improvement in the working efficiency has been made.
On the contrary, digital video materials such as (video) materials collected (gathered) in the drama, etc., which require high picture quality, require high transfer rate. In the case of production house, etc. which cannot ensure channels of SNG, as shown in FIG. 8, these digital video materials are recorded onto a magnetic tape to carry convey this magnetic tape to thereby carry out delivery (transfer) of video material.
Meanwhile, also in such production house, etc., if delivery of video materials can be made by using communication line, the time required for delivery is shortened accordingly. Thus, the working efficiency can be improved.
As one method thereof, a method in which B-ISDN which is one of public lines which can be easily utilized even in the production house of this kind is used to carry out transmission of video materials of this kind is conceivable.
However, the transmission system of the video material applied to (transmission equipment within) the production house, etc. is the synchronous transfer system in which video signals are caused to undergo transmission (transmitted) without break on real time basis, whereas in the case of the transmission system by B-ISDN, data are caused to undergo transmission (transmitted) by the asynchronous transfer mode for intermittently transmitting data with respective cells being as unit. There is great difference therebetween in respect of the above-mentioned point. Accordingly, in the case of the transmission system by B-ISDN, there was the problem that it is impossible to easily carry out transmission of video materials of this kind.
Further problem is that the fact that the transfer rate of video materials of this kind is greatly different from the transfer rate of B-ISDN also makes it difficult or impossible to easily carry out transmission of video materials of this kind.
This invention has been made in view of the above-mentioned problems, and its object is to provide a video signal transmission apparatus capable of transmitting/receiving video materials by the synchronous transfer system by using the transmission path by the asynchronous transfer mode.
A video signal transmitting/receiving apparatus is directed to a video signal transmitting/receiving apparatus adapted for converting a series of video signals into picture data in predetermined block units to send out it to a transmission path in the asynchronous transfer mode to thereby transmit a first video material formed by the series of video signals to transmission object (object which is subject to transmission), and adapted for receiving picture data inputted in the predetermined block units by the asynchronous transfer mode through the transmission path to convert it into a series of video signals to receive a second video material formed by the series of video signals transmitted from transmission object, the apparatus comprising: recording/reproduction means for recording or reproducing the first or second video material with respect to (i.e., onto or from) a recording medium; memory means for storing the first video material outputted from the recording/reproduction means or the second video material inputted through the transmission path; and control means for monitoring memory (storage) speed when the first or second video material to be stored into the memory means is (actually) stored thereinto, and for monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value when the first video material is transmitted from the memory means to the transmission path, the control means outputs, to the recording/reproduction means, a control signal in which reproduction speed of the recording/reproduction means is designated along with a control signal for controlling the recording/reproduction means to allow it to reproduce the first video material recorded on the recording medium, and in the case where the remaining capacity of the memory means is less than the predetermined value when the second video material is stored into the memory means from the transmission path, the control means outputs, to the recording/reproduction means, a control signal in which recording speed of the recording/reproducing means is designated along with a control signal for allowing the memory means to output therefrom the second video material stored therein to allow the recording/reproduction means to record it.
Moreover, a video signal transmitting apparatus according to this invention is directed to a video signal transmitting apparatus adapted for converting a series of video signals into picture data in predetermined block units to send out it to a transmission path in the asynchronous transfer mode to thereby transmit a video material formed by the series of video signals to transmission object, the apparatus comprising: recording/reproduction means for recording or reproducing the video material with respect to (i.e., onto or from) a recording medium; memory means for storing the video material outputted from the recording/reproduction means; and control means for monitoring memory (storage) speed of the video material stored in the memory means, and for monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value when the video material is transmitted from the memory means to the transmission path, the control means outputs, to the recording/reproduction means, a control signal in which reproduction speed of the recording/reproduction means is designated along with a control signal for controlling the recording/reproduction means to allow it to reproduce the video material recorded on the recording medium.
Further, a video signal receiving apparatus according to this invention is directed to a video signal receiving apparatus adapted for receiving picture data inputted in predetermined block units by the asynchronous transfer mode through a transmission path to convert it into a series of video signals to thereby receive a video material formed by the series of video signals transmitted from transmission object, the apparatus comprising: recording/reproduction means for recording or reproducing the video material with respect to (i.e., onto or from) a recording medium; memory means for storing the video material inputted through the transmission path; and control means for monitoring memory (storage) speed of the video material stored in the memory means, and for monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value when the video material is stored into the memory means from the transmission path, the control means outputs, to the recording/reproduction means, a control signal in which recording speed of the recording/reproduction means is designated along with a control signal for allowing the memory means to output therefrom the video material stored therein to allow the recording/reproduction means to record it.
Further, a video signal transmitting/receiving method according to this invention is directed to a video signal transmitting/receiving method of converting a series of video signals into picture data in predetermined block units to send out it to a transmission path in the asynchronous transfer mode to thereby transmit a first video material formed by the series of video signals to transmission object, and of receiving picture data inputted in the predetermined block units by the asynchronous transfer mode through the transmission path to convert it into a series of video signals to thereby receive a second video material formed by the series of video signals transmitted from transmission object, the method comprising: a first step of recording or reproducing the first or second video material with respect to (i.e., onto or from) a recording medium; a second step of storing, into memory means, the first video material reproduced from the recording medium or the second video material inputted through the transmission path; and a third step of monitoring memory (storage) speed when the first or second video material to be stored into the memory means is (actually) stored thereinto, and monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value, such a control is conducted to allow the recording/reproduction means to reproduce the first video material recorded on the recording medium at a reproduction speed corresponding to the memory speed, and in the case where the remaining capacity of the memory means is less than the predetermined value when the second video material is stored into the memory means from the transmission path, such a control is conducted to allow the recording/reproduction means to record, onto the recording medium, the second video material stored in the memory means at a recording speed corresponding to the memory speed.
Further, a video signal transmitting method according to this invention is directed to a video signal transmitting method of converting a series of video signals into picture data in predetermined block units to send out it to a transmission path in the asynchronous transfer mode to thereby transmit a video material formed by the series of video signals to transmission object, the method comprising: a first step of recording or reproducing the video material with respect to (i.e., onto or from) a recording medium; a second step of allowing memory means to store thereinto the video material reproduced from the recording medium; and a third step of monitoring memory (storage) speed when the video material to be stored into the memory means is (actually) stored thereinto, and monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value when the video material is transmitted from the memory means to the transmission path, such a control is conducted to allow the recording/reproduction means to reproduce the video material recorded on the recording medium at a reproduction speed corresponding to the memory speed.
Further, a video signal receiving method according to this invention is directed to a video signal receiving method of receiving picture data inputted in predetermined block units by the asynchronous transfer mode through a transmission path to convert it into a series of video signals to thereby receive a video material formed by the series of video signals transmitted from transmission object, the method comprising: a first step of recording or reproducing the video material with respect to (i.e., onto or from) a recording medium; a second step of allowing memory means to store thereinto the video material inputted through the transmission path; and a third step of monitoring memory (storage) speed when the video material to be stored into the memory means is (actually) stored thereinto, and monitoring remaining capacity of the memory means, whereby in the case where the remaining capacity of the memory means is less than a predetermined value when the video material is stored into the memory means from the transmission path, such a control is conducted to allow the recording/reproduction means to record the video material onto the recording medium at a recording speed corresponding to the memory speed.
Thus, in accordance with the invention respectively featured as above, when applied to a video signal transmission apparatus adapted for sending out a series of video signals to the transmission path by the asynchronous transfer mode to transmit video material to the transmission object, and adapted for receiving picture data inputted by the asynchronous transfer mode through the transmission path to receive video material, thus to transmit the video material, such a transmission system is employed to record a series of video signals onto the video signal recording medium thereafter to intermittently reproduce the video signal recording medium in dependency upon empty state of the transmission path to convert reproduction signals obtained by the reproduction into picture data of the previously prescribed block units to transmit it to the transmission object, thereby making it possible to send out video signals inputted by the synchronous transfer system, e.g., in cell units in correspondence with circumstances of the transmission path. Moreover; also in the case where the sending-out speed of cell varies, this transmission system can cope with such a case. Further, when such a transmission system is employed, in receiving video material, to record video signals obtained from the previously described picture (video) data onto the previously described video signal recording medium thereafter to reproduce, when, with respect to a series of video signals, reception of picture data corresponding thereto is completed, the recorded series of video signals and to output them, even in the case where, in reception of picture data intermittently transmitted by the asynchronous transfer mode, the time interval of the picture data intermittently obtained (i.e., cell data) is varied, this transmission system can cope with such case.
Further, at this time, if the previously described video signals are caused to be digital video signals by the prescribed format, the video signals can be caused to undergo recording/reproduction by the data recorder.
Furthermore, at this time, if the previously described video signal recording medium is caused to be comprised of magnetic tape, e.g., data recorder adapted for recording/reproducing digital video signals by the prescribed interface is used, thus making it possible to record/reproduce the video signals.
In addition, in place of the above, if such a transmission system is employed to input/output picture data from and to the previously described transmission path through the prescribed buffer memory to change recording speed or reproduction speed of the video signal recording medium in correspondence with input/output of the previously described picture data from the buffer memory, it is possible to finely cope with change of time intervals of respective cells, etc.